Turnipseed S B, Roybal J E, Plakas S M, Pfenning A P, Hurlbut J A, Long A R
U.S. Food and Drug Administration, Animal Drugs Research Center, Denver, CO 80225, USA.
J AOAC Int. 1997 Jan-Feb;80(1):31-5.
Methylene blue (MB) is a thiazine dye that, although not regulated for use with edible fish, may sometimes be used as a chemotherapeutic agent in the aquaculture industry. A liquid chromatographic (LC) method was developed for the determination of MB in fish muscle. MB was extracted from catfish tissue with an acetonitrile-acetate buffer solution containing hydroxylamine and toluenesulfonic acid, partitioned into methylene chloride, and cleaned up on alumina and carboxylic acid solid-phase extraction cartridges. MB concentrations were determined by LC with visible detection at 660-665 nm. Recoveries of MB from catfish fortified at 10-50 ng/g were 75-90% (RSDs, 5-12%). Leucomethylene blue also can be recovered from catfish tissue as the MB colored form at low levels with similar recoveries. Analysis of catfish exposed to MB in a bath treatment at 5 ppm MB for 1 h recovered 10-20 ppb of the drug in the muscle tissue. The low tissue concentration suggests poor absorption of this drug compared with other antifungal dyes that tend to concentrate and remain in fish tissue at high levels.
亚甲蓝（MB）是一种噻嗪染料，尽管未被规定用于食用鱼类，但在水产养殖业中有时可作为一种化疗剂使用。开发了一种液相色谱（LC）方法用于测定鱼肉中的亚甲蓝。用含有羟胺和甲苯磺酸的乙腈 - 醋酸缓冲溶液从鲶鱼组织中提取亚甲蓝，将其分配到二氯甲烷中，并在氧化铝和羧酸固相萃取柱上进行净化。通过在660 - 665 nm处进行可见检测的液相色谱法测定亚甲蓝浓度。在鲶鱼中添加浓度为10 - 50 ng/g的亚甲蓝后的回收率为75 - 90%（相对标准偏差为5 - 12%）。无色亚甲蓝也可以从鲶鱼组织中以低水平的亚甲蓝有色形式回收，回收率相似。对在5 ppm亚甲蓝的浴液处理中暴露1小时的鲶鱼进行分析，在肌肉组织中回收了10 - 20 ppb的该药物。低组织浓度表明与其他倾向于在鱼组织中高浓度浓缩并残留的抗真菌染料相比，这种药物的吸收较差。
